Imagine you are just walking around the solid rock under your feet starts to crackle and then POP as pieces fly apart. This doesn’t normally happen.
One interesting way that rocks weather and crumble apart is called “exfoliation.” Like the skin-scrubbing technique, this involves the outermost layers of exposed igneous or metamorphic bedrock sloughing off in a sheet.
Typically, you can observe the results of this type of weathering, but it’s not every day that you can catch it in the act. For some reason (and to the delight of curious geologists), an outcrop of granite alongside the dam that forms Twain Harte Lake in California has recently begun exfoliating vigorously.
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The dome of granite is exfoliating and will eventually have a smooth, rounded appearance. Unfortunately, this outcrop is near a dam and surface damage is occurring. Technology has been installed to monitor the activity which comes in bursts as stress is relieved in the rock. It’s not known how long it will last. It’s also not known if this is going on elsewhere in the world. But I have to wonder what this looks like at night and if it emits lights (like a Life Saver candy cracked with a hammer) in a piezoelectric effect.
More on exfoliation, part of the process that turns rock eventually into sand, grain by grain.
Tip: Tim Farley